Gilmore played college basketball at Jacksonville, leading the team to the NCAA championship game against UCLA in 1970. He was drafted in 1971 by the Chicago Bulls and the Kentucky Colonels, choosing the play in the ABA. In 1972, he won the ABA Rookie of the Year and MVP he was an all-star all five years in the ABA (1972-'76), and led the Colonels to the 1975 ABA Championship. Since the Colonels folded during the ABA/NBA merger, Gilmore was the first pick in the dispersal draft by the Bulls. He played for Chicago from 1976-'82, then the San Antonio Spurs from 1982-'87, the Bulls again in 1987-'88 and finished his career with the Boston Celtics in 1988. He was an NBA All-Star six times (1978, '79, '81-'83 & '86). Gilmore was inducted into Basketball Hall of Fame in 2011.